1. Field of Invention
The present invention generally relates to an optical transmitter, more particularly to an optical communication transmitting device in a SoC (system on chip) for reducing the size and cost of the device.
2. Description of Related Arts
With bandwidths of up to 10 Gb/s have been demonstrated the practical upper limit of such a system has not yet been determined, optical communication systems are fast-growing areas in communication networks. The “optical communication system” pertains to any system that uses optical signals to convey information across an optical waveguide medium, such as an optical fiber. An optical waveguide generally consists of a core section configured to propagate an optical carrier signal within the core, and a cladding section surrounding the entire periphery of the core section. Optical elements employing such an optical waveguide include, i.e., an optical power splitter/coupler for splitting or coupling the optical power of the optical signals, and a wavelength division multiplexer/demultiplexer for multiplexing or demultiplexing multiple channels of the optical signal according to the wavelengths selected. A Y-branched optical waveguide is typically used for splitting optical power, and includes an input waveguide for receiving the optical signal, a fiber waveguide for extending the transfer mode of the input optical signal, and a pair of output waveguides for branching out the optical power of the extended optical signal to provide the branched optical power as an output optical signal.
Nowadays, optical elements, such as optical waveguides, are made of optical fibers. Therefore, the size and cost of the optical waveguides are not effective. According to the drawbacks aforementioned, the present invention provides an optical communication transmitting device and method of manufacturing the same for reducing the size and cost of the device.
U.S. Pat. No. 5,633,966 discloses a method for forming refractive index distribution in light transmission path, and optical filter and method of using the same. The method comprises the steps of comprising the steps of: (a) preparing a light transmission path including a core and a cladding layer; (b) applying a photosensitive material layer onto a surface of said cladding layer; (c) patterning said photosensitive material layer by photolithography thereby forming a mask pattern; and (d) irradiating said light transmission path with an X-ray through said mask pattern, thereby forming in said core a refractive index fluctuation distribution corresponding to said mask pattern. The method teaches the way for forming refractive index distribution in light transmission path by photolithography and X-ray irradiating, but the method dos not teaches the way for forming waveguides.
U.S. Pat. No. 5,915,051 discloses a wavelength-selective optical add/drop switch. The wavelength-selective optical switch comprises: a first input port for accepting a plurality of copropagating optical channels, a first output port, a second output port, wavelength-selective optical filter means connected to receive the copropagating optical channels from the first input port to extract a selected one of the channels while allowing remaining channels to copropagate to the first output port, and an interferometric switch connected to receive the selected extracted channel. The switch is a waveguide for transmitting optical signals with different wavelengths. However, the size and cost of the switch is not benefit.